Dovetailing-machine



W. A. MCDONALD, OFMOIT HAVEN, NEW YORK.

DOVETAILING-IVIACHINE.

Specification of Letters Patent No. 22,967, dated February 15, 18'59.

To all whom it 'may concern: l

Be it known that I, W. A. MCDONALD, of Mott I-Iaven, in the county of IVestchester and State of New York, have invented a new and Improved Dovetailing-h/Iachine; and I do hereby declare that the following is a full, clear, and exact description of the same, reference being had to the annexed drawings, making a part of this specification, in which- Figure l, is a transverse vertical section of my invention taken in the line ai, Fig. 2. Fig. 2, is a front view of ditto. Fig. 3, is a plan or top view of ditto, the cutter head being bisected longitudinally and horizontally. l

Similar letters of reference indicate corre spending parts in the several figures. y

This invention consists in a cutter head constructed in a novel way as hereinafter fully shown and described and used in connection with an adjustable bed, so as to form one portion of dove tail joints' by a continuous operation and in a rapid and perfect manner.

To enable those skilled in the art to fully understand and construct my invention I will proceed to describe it.

A, represents a framing which may be constructed of wood as follows two heavy pieces of plank a, a', being fitted together in V-form and secured at each end to a support Zi.

On the upper edge of the plank a', two bearings c c are secured, and a shaft B, is fitted in those bearings. To the outer end of the shaft B, a crank C, is attached, and on the inner end a cutter head D, is secured, Saidl cutter head being at about the center of the upper edge of the front plank a, as

shown in Figs. 2 and 3.

To the back plank a, of the frame A, a bed plate E, is attached by arms d, d, an arm being attached to each end of the plank a, and said arms being pivoted to both the plank and the bed piece. The bed plate E, rests on screws e, which are fitted vertically in the angle of the planks a, a', and number of screws e, may be used. By raising or lowering the screws e, the front part of the bed plate E, may be raised or lowered relatively with the cutter head D, as desired. This will be clearly understood by referring to Fig. l.

The cutter head D, is constructed as follows g-A cylindrical head f, is placed permanently on the shaft B, and on this head there is a spiral thread g, the outer surface or face of which gradually increases in thickness from the front to the back end of the head f, see more particularly Fig. 2. The thread g, at its junction with the head f, is of equal thickness throughout as shown clearly in Fig. 3, but the thread gradually projects farther from the head f, as it approaches the back end of head f.

From the above description it will be seen that the cutter head may be very readily constructed by cutting a simple dovetail screw thread on the cylindrical head f, and then turning the face of said thread so as to form a conical exterior on the head On the face of the thread g, cutters t, are formed, in any proper way. These cutters may be formed by serrating the face of the screw thread g, or cutters may be inserted in the thread, according to the size of the cutter head.

lThe operation is as follows The work a", to be dovetailed, shown in red, is placed liatwise on the bed-plate E, which is ad justed relatively with the cutter head D, as may be desired, and one edge of the work is placed against the front end of the cutter head D. The shaft B, is then rotated and the cutters it, of the screw thread g, act upon the edge of the work, cutting dovetail recesses in it and the screw g, feeding the work along, see Fig. 3. It will be seen that the cutter head D, cuts only one portion of the dovetail the corresponding inverse portion to be joined to the work ax, being performed by hand or by another machine which will be the subject of a future application for Letters Patent'.

By this invention the position of the dovetail described may be cut with great rapidity and by a continuous operation.

The invention is extremely simple and the cost of construction triling.

I-Iaving thus described my invention what I claim as new and desire to secure by Letters Patent, is,

The cutter liead D, formed of a screw thread g, on a cylinder f, the screw thread being provided with cutters 7L, and arranged substantially as described and for the pur pose set forth. y

W. A. MCDONALD.

Witnesses:

Vn. TUscH, W. HAUPF. 

